Exhaust turbine blading



Oct. 19-, 1926;

- 1,603,303 E- ZETTERQUIST v EXHAUST TURBINE BLADING Filed Dec. 21, 1923 Illlllllllllllllillll' lNVENTOR ATTO R N EY :EIRIQ zErrERQuIsr; or ssInGTo'N. PnNns LvAnm;: .AssIq1\ToR To WESTINGHOUSE e "ELECTRIC AND emrnacrumne COM NY; A 0032034112191; 'or'PENNsYLvAnIA. v

nx mns r romaine Bra-m re.

Application fiIed DeceInberZ-I, .1922. "saga nol iesaloi.

" My inventionrelates tod'elastio-fluid turbines and it has foranobject to. provide,

exhaust orlow pressure blading for appara tusofthis character which". shall be capable of handling large volumes of low-pressure elastic fluid efliciently' with little, if any, loss due to drop in pressure in the motive fluid as it passes between the blades. e

More particularly, my invention relates to wide blading of'the lateral-receiving and peripheral-discharging. type" and it has for 'an' obj'ect'to provide'blading of this character' having energy-abstracting portions arr'angedat small angles and which allows for change in direction of flow without necess1- tating an increase in area between the in let and outlet side so as to avoid substantial drops in pressure between the b1ade'ele ments.

Apparatus embodying features of my invention is illustrated in. the accompanying "drawing, forming a part of I this application in which: 'Fig, 1-"is af sectionaldetail view of a turbine showing my: improved low-pressure bladingapplied thereto; Fig.

2'is a section taken along the linesII-,-II of Fig. 1; Fig.8 is asectiontaken along "the line IIIIII of Fig. 1:; Fig. 4 is a view similar to Fig. 1' but showing a modified a1",- range' nent of" low-pressure ,blading and Fig. 5 is a perspective View of adjoining portions of a pair of low-pressureblade elements. I

' In my application, Serial No. 682,102 filed December 21, 1923and assigned to'theWV'est 'inghouse Electric and ManufacturingGompany,'I have'disclosed' and claimed a type of moving exhaust blading wherein :the' blades are arranged to divide the steam for dischargefrom a plurality of rows of energy abstractin'g elements so that motive fluid passages betweenthe blades may be provided which do not increase in area substantially' from the inlet to thefexit, thereby avoidinglosses, due to drop in pressure as the motive fluid passes" between the blades. In other words, a multiple exhaust 10W.

pressure .movingblade construction is ro VlClBtlWheI'eintlle total passage area ro-mf ,the inlet sidetowards; the outlet side or the Zcellulariblade construction set forth I in my application aforesaid is'iemployed but the energy-abstracting elements are modified.- -Fixed guide vanes defining; expan s1on passages are-provided for directing motive fluld into itheF,-Inoving-blade structure; and the moving blade :structure 'is' provided with energy-abstracting elements of the impulse or impact type at both sides i and at the-tips, although the latter -'e le ments maybe of the type set forth in my said application;

' In the patent/of .Alexand'er N05 1 469 925, issued ()ctoloerfl, 1923 ,ai1d assigned to; the .Westinghouse Electric and Manufacturing]Company,there is disclosed and claimed wide lolading having peripherally-discharging, energy-abstracting? portions which. are" of the spoon-outline itype. :In accordance ;w1th-;my present inyention,

Ipropose' als'o'to use 'blading ofthisftype V tvhich is immediately precededf by' a moving row of imp'ulsei elements adaptedfltoj're- "CelVB motlve. fluid discharged fromffexpana sion' passagesdefinediby a stationary row of guide vanes. a 1

- Referring now to the'drawings for a more 'detalled; dGSOIlPtlOll of my invention,- in

Fig. 1, IshoW a turbine-comprising a rotor 10. and. a casing or: cylinder '11 providedwith 'bladingof any f'suitabl'e type followed by my improvedlow-pressureior exhaust stage consisting of guide blades-12 definingexpansion passages, carriedjbythe casing, and

Wide bla de'structures 13, carried by the rotor;

The wide blade structures include himat" a small angle as "indicated by] the anglev through inter-group spaces at 1 8 'an1 toggle pulse bladeelenc ents. or buckets 14 arranged to receive motor" fluid: discharged'by theguide blades 12 and which contact with. the

blade elements -1'5.'=.the latter "contacting. in groups oftwo at 'theftipsgfas shown-in?F-ig.., 3, to provide; energy-abstracting portions T '16 defining dischargepassages 1-7 arranged fine cellular passages at The low-pres sure moving blade structure also includes impulse elements which are adapted to cover the inter-group spaces 19 at the outside and a'vhich'; define discharge passages 21 arranged at a small angle as indicated'by the angle ,8 in Fig. 2 for said cellular passages19.

The, opposed faces/ ot {the plate; or blade 1 elements 15, which define the inter-group spaces 18, are provided with suitable jdeflec tor structure 22 to gradually change the direction otflow of motive fluid in the-in ter-group spaces 18 from an axial to a radial direction: Similarl the op osed faces of blade elements 15, wl'i'i'clrdefine the spaces 19, are;provi'ded?witli s'uitab'le' guide plates 23 to maintain 'the motive fluid in a straight I 1 paeuumagrv the spaces 19.

The inactive spaces;2 l, formed by blade elements .1-5, ii'npulse elements 20'a'nd deflectors 22, constitute a special feature of this type of exhaust 'bla'destructure, inasmuch as they repres ent a' corresponding amount or "solid material which for the proper design of annula'nbl'ad'e structures, not emwhich define spaces communicating alternately with" the peripheral and lateral energy-ab'st rac'ting fele'1'nents16 and 20', respectively. Thus, all of the available pressure energy in the motive fluid is converted into velocity-energy by the stationary blades 12 -and,r11er-eafter, this velocity energy is abstracted by-the impulse or impact elements 14:, 16, and 20. The impulse elements 14, the registering plate elements 15 at the forward *s'i des'ozr the inter-group spaces 18, and

the "elements 16, in effect, constitute single impuls-e'blade elements, and impulse elements 14 together with plate elements '15, guide plates 23-and impulse elements 20 constitute,

in effect, impulseblade elenients for the motive rflu'id "passing through the cellular spaces 19.

The cellular construction of the moving blade structure 13 makes'it'p'ossible to pro- 3 vide a total exit area"adjacentto-the energyabstracting'portions:'-16and '20 which is not tgreaten than the discharge area of the 'im- 'pul se'elements: ln this way, losses due to dropsLin pressure between the plate or blade :e'l-emer its are substantially avoided. Al-so, thisc'onstructionpermits, not only of "ther-advantageoi is relation of areas pointed out, but" also of u ample discharge area, for

stea-miat;smallleaving angles. f c

In Figs. 4 and 5, I show a modified form of exhaust blades 25 following the guide blades 26 adapted to expand and to discharge motive fiuid at a proper angle for entry between the moving impulse or impact elements 27 at the entrancesidc-s-of the moving exhaust blade structures 25. The moving exhaust blade structure is furthermore comprised by blade. elements having inner radialportions28 which contactand register with the discharging sides of the impulse elements 27 and which are provided with outer curved or spoon-outline energyabstraotii'igiip-ontisons :29, such as disclosed and claimed in the patent to Alexander T. Kfasle'y aforesaid. Suitable guide 1 members 30 are {carried by the blade portions 28j to co'i'i'stitute guides orl deflectorsto change the direction of flow ot Il'lOtlVBa fluid, from an axial toward a radial direction.foriaction upon the energy-abstracting. portions 29'. r

It is to be understood that the-.energy-ab; straeting portions 1'6 and 20 in. Figs. 1,2 ands maybe, in action, either predominantly impulse or reaction. It is essential, however, that the guide blades--12 of Fig. lsh'a-ll ex p'and themotive fluid so. vas;to.discharge.it to the low-pressure movingwblade' structure at a high ive locit y and at -.a relatively. low pressure. 1,; therefore,- prefer that the en.-

ergy-abstracting portions at the Etips andeat the 'outer sides of the -lowepress'ure moving blade structure ofi gs. 1, 2:and 3Jsha-llybe of the impulse type so that the motive=fluid may be: 'at the lowest practicable;pressure when it: is discharged 'by'the 'fixedguide vanes; however, as already 1 stated, the motive fluid maybe discharged,frornqthe guide vanes with suliicient-resid-ual pressure so that further expansion maybe carried on by reaction expansion passagesdefined by en ergy-abstra'cting portions. arranged peripherally and laterally. The latter scheme jis involved in 2 the "modification disclosedinfFifg. 4, whereinthe motive fluid has pressure energy. changed into-velocity energy by the guide vanes '26, but itisadischarged ffOillzfllE latter at a suflicient pressure for further expansion by the peripherally-arranged, reaction,- energy-abstracting portions 29. p From :the. toregoing,=1t w ll be apparent that I have devlsed amultiple-exhaustlowpressure' blade =st ructure,; provided -:ZW1lll1 pas- "sage 2 areas arranged. n such! a manner 7 as to avoid losses due "to; drop in pressure as the motive fluid-passes from T the later'al inlet side -to the lateral and peripheral out-letsides of -my blade. structure,,the' available pressure energy offethe'motive fluid having been partly or wholly converted into velocity energy by. a stationary row of blades or nozzles betore the Emotive fiuid enters themoving bladejstructure. 1

VVh-ile I have shownmy invention inibut two forms, it wilLbe "obvious to those skilled in the art that it is not so limite ch but is ins o prising a row of fixedblades defining ex 'ture having energy-abstracting"portions at si'isceptible'gofvarious other changes and modifications, without departing 'fromi the' spirit thereof,"and I desire, therefore, that only such limitations shall b-e placed:there-' theinlet and at thetips. V V

In a turbine, a low-pressure stage comprising a row of stationaryvanesfollowed by a cellular blade structure having energy-f abstracting portions at the inlet side and de fining passages which lead to peripheral and lateral energy-abstracting portions.

L111 a turbine, an exhaust blade structure comprising radially arranged impulse blade elements followed by wideblade ele .having peripherally-arranged ments arranged adjacent 'thereto,'adapted to jreceive motive fluid therefronnand having peripherally arranged energy abstracting portions. I

'5. In a turbine, an exhaust blade structure having energy-abstracting portions of the impulse type at the sides and at the tips.

6. In a turbine, an exhaust blade structure having energy-abstracting portions of the impulse type at the inlet side and at the tips.

7 In a turbine, a row of radially-arranged impulse elements merging into a wide blade stractin'g portions. r 4

8. In a turbine, a row of stationary blades adapted to convert pressure energy into velocity energy followed by a row of impulse elements contacting with blade elements havingenergy-abstracting portions at the tips thereof.

'9. In a turblne, a low-pressure stage come pansion passages followed by a moving'-' row blade construction which includes a row of impulse elements, a row of wide blade elements contacting with the impulse elements, said wide blade elements contacting at their tips in groups of two todefine energy-abstrac'ting portions for the motive fluid ,received' in the inter-group spaces and to define cellular passages, and a row of elements for abstracting energy from the motive fluid flowing through said cellular passages.

10. In a turbine, a moving blade construetion comprising impulse elements which 1 merge into flat plate elements disposedsub in. the appended.

energy-ab stantially in axial planesandwhavinjg alternatingf peripheral -:andg lateral energy-ab; stractin g portions forthe motive fluid, pass:

ing-between theplate elements;

4.511.111 a turb nei low-pressure comprising-a rowz ofwfixed vanes defining ex: pans'ion passages followed by army of m pulse blade elements contacting with flatplate elements arranged substantially in axial planes and which contact attheirtips to define alternating periph erally-open and closed spaces between the plate elements and to'xdefine energyabstracting portions for the motive fluid passing in said peripherally-open spaces, and impulse elements to reperipherally-closed spaces.

*ceive themotive fluid flowing through said f 12. In a turbine,ga row of stationary blades, a row of impulseelements, rows of impulse elements followingsaid first row of impulse elements, and means forconductf ing motive fluid from said first'row of impulse elements to saidlatter rows of impulse elements, V

- 13. In a turbine, the combination of a row elements following said first row of impulse elements, and means for conducting motive fluid discharged from said first row of im-.

pulse elements alternately to said latter rows of impulse element s;

14, In a turbinepthe combination of a roWof stationaryvanes,,a row ofenergye abstracting elements followed by two other [rows of energy-abstracting" elements and means for conducting motive fluid discharged by said first row of energy-abstracting elements alternately to. said latter rows.

- 15. V Ina turbine, the combination of a row of fixed guide, vanes'deflning expansion pas sagesadapted'to discharge motive fluid in an axial direction, a row of blade eleof guide vanes defining-expansion passages,

a row of impulse elements, rows of lmpulse ments adapted to abstract energy from motive fluid flowing in an axial direction, peripherally and laterally-discharging energy-abstracting elements,and means for v conducting motive fluid discharged from said blade elements alternately to the peripheral and lateral discharging energy-abstracting elements. 7 16. In a turbine, va row of stationary blades followed by a moving blade construe-j tlonwhich comprises inlet impulse elements followed by elements which define alternately arranged energy-abstracting portions so that the total passage area between the en ergy abstra'cting portions and the discharge side of saidimpulse elements may be'maintained equal to or be made less than the total discharge area of said impulse elements,

vwherebyyelocity loss ofthe motive fluid due to drop: 1n pressure in passing to said energy-abstracting portions is substantially avoided,

17 In'a tiirbine,'a rw of blade elements having im ulse 'pbrtions at the inlet edges thereof and alternately-arranged periphera1 and lateral fier'gy-absbfacting portions;

i whereby the latter 'po'r tio ns may be designed for efliciefit Operation and the sum of any two passage areas thrdugh the blade st-ruc ture is equal to 01" les's 'tha'n the discharge areas of said impulse portions to avoid elocity loss in the motive fluid passingto the peripheral and lateral energy-abstracting ber, 1923. l e ERIC ZETTERQ'UIST; 

